Y.-C. Chen, D.-Y. Yang / Tetrahedron 69 (2013) 10438e10444
10443
12.2; IR
n
(KBr) 1614, 1502, 1198, 1027, 747 cmꢂ1; HRMS (EI) m/z
n
(KBr) 3238, 1610, 1535, 1354, 749 cmꢂ1; HRMS (EI) m/z calcd for
calcd for C15H13BrN2O [Mþ] 316.0211, found 316.0205.
C
15H13N3O3 [Mþ] 283.0957, found 283.0951.
4.3.6. 2-(2-Chlorophenyl)-4-methyl-1,2-dihydroquinazoline 3-oxide
4.4. General procedure for the preparation of compounds
(1f). Yellow solid; yield 85%; Rf¼0.2 (70% EtOAc/hexanes); mp
4aej
176e177 ꢀC; 1H NMR (CDCl3, 300 MHz)
d
7.40 (dd, J¼7.8, 1.2 Hz, 1H),
7.29 (dd, J¼7.8, 1.2 Hz, 1H), 7.24 (dd, J¼7.8, 1.8 Hz,1H), 7.18 (td, J¼7.8,
1.2 Hz, 1H), 7.13 (dd, J¼7.5, 1.2 Hz, 1H), 7.08 (dd, J¼7.5, 1.8 Hz, 1H),
6.87 (td, J¼7.8, 1.2 Hz, 1H), 6.62 (dd, J¼7.8, 1.2 Hz, 1H), 6.53 (d,
J¼2.1 Hz, 1H), 5.15 (s, 1H), 2.59 (d, J¼0.6 Hz, 3H); 13C NMR (CDCl3,
A dried 250 mL round bottom flask was charged with 1
(0.5 mmol) and CH3CN (100 mL) at room temperature. The result-
ing mixture was placed at a distance of approximate 10 cm from
a 23 W fluorescent lamp (Philips essential 57 lm/W, 6500 K) and
was irradiated for 16e18 h. The solvent was then evaporated and
the photogenerated product was purified by column chromatog-
raphy (1:4 EtOAc/hexanes) to give the pure compound.
75 MHz)
d 142.8, 138.6, 134.2, 132.7, 130.5, 130.3, 130.2, 127.4, 127.1,
124.5, 120.0, 117.2, 114.7, 77.6, 12.4; IR n (KBr) 1614, 1502, 1197, 1035,
746 cmꢂ1; HRMS (EI) m/z calcd for C15H13ClN2O [Mþ] 272.0716,
found 272.0720.
4.4.1. 4-Methyl-2-phenylquinazoline (4a). White solid; yield 90%;
Rf¼0.8 (20% EtOAc/hexanes); mp 90e91 ꢀC (lit.5c 89e90 ꢀC); 1H
4.3.7. 2-(2,4-Dichlorophenyl)-4-methyl-1,2-dihydroquinazoline 3-
oxide (1g). Light yellow solid; yield 82%; Rf¼0.2 (70% EtOAc/hex-
NMR (CDCl3, 300 MHz)
d
8.61 (dd, J¼8.4, 1.8 Hz, 2H), 8.07 (dd, J¼8.4,
anes); mp 167e168 ꢀC; 1H NMR (CDCl3, 300 MHz)
d
7.42 (d,
1.8 Hz, 2H), 7.85 (ddd, J¼8.4, 6.9, 1.5 Hz,1H), 7.59e7.48 (m, 4H), 3.00
J¼2.1 Hz, 1H), 7.29 (dd, J¼7.8, 1.5 Hz, 1H), 7.16 (dd, J¼8.4, 2.1 Hz, 1H),
7.13 (td, J¼7.8, 1.5 Hz, 1H), 7.04 (d, J¼8.4 Hz, 1H), 6.89 (td, J¼7.8,
1.5 Hz,1H), 6.63 (dd, J¼7.8,1.5 Hz,1H), 6.48 (d, J¼2.4 Hz,1H), 5.20 (s,
(s, 3H).
4.4.2. 4-Methyl-2-(4-isopropylphenyl)quinazoline (4b). Yellow liq-
uid; yield 92%; Rf¼0.7 (20% EtOAc/hexanes); 1H NMR (CDCl3,
1H), 2.57 (d, J¼0.9 Hz, 3H); 13C NMR (CDCl3, 75 MHz)
d 142.6, 138.2,
135.5, 133.4, 132.7, 130.4, 129.9, 128.1, 127.5, 124.5, 120.3, 117.1, 114.6,
300 MHz)
d
8.52 (d, J¼8.4 Hz, 2H), 8.08 (d, J¼7.5 Hz, 1H), 8.06 (d,
76.4, 12.3; IR
n
(KBr) 3279, 1590, 1483, 1204, 752 cmꢂ1; HRMS (EI)
J¼8.4 Hz, 1H), 7.85 (ddd, J¼8.4, 6.9, 1.5 Hz, 1H), 7.56 (ddd, J¼8.4, 6.9,
1.2 Hz,1H), 7.38 (d, J¼8.1 Hz, 2H), 3.01 (s, 3H), 2.99 (septet, J¼6.9 Hz,
m/z calcd for C15H12Cl2N2O [Mþ] 306.0327, found 306.0320.
1H), 1.31 (d, J¼6.9 Hz, 6H); 13C NMR (CDCl3, 75 MHz)
d 167.9, 160.2,
4.3.8. 2-(4-Fluorophenyl)-4-methyl-1,2-dihydroquinazoline 3-oxide
151.3, 150.3, 135.9, 133.3, 129.0, 128.5, 126.55, 126.46, 124.8, 122.7,
(1h). Yellow solid; yield 76%; Rf¼0.2 (70% EtOAc/hexanes); mp
34.0, 23.8, 21.9; IR
n
(KBr) 2960, 1609, 1493, 1179, 762 cmꢂ1; HRMS
177e178 ꢀC; 1H NMR (CDCl3, 300 MHz)
d
7.50 (d, J¼8.4 Hz, 1H), 7.48
(EI) m/z calcd for C18H18N2 [Mþ] 262.1470, found 262.1469.
(d, J¼8.4 Hz, 1H), 7.23 (dd, J¼7.8, 1.2 Hz, 1H), 7.18 (dd, J¼7.8, 1.2 Hz,
1H), 7.00 (d, J¼8.4 Hz,1H), 6.98 (td, J¼8.7, 1.8 Hz, 1H), 6.91 (td, J¼7.8,
1.2 Hz, 1H), 6.81 (d, J¼7.8 Hz, 1H), 6.11 (d, J¼3.3 Hz, 1H), 4.97 (br s,
4.4.3. 4-Methyl-2-(4-methoxyphenyl)quinazoline
(4c).5j Yellow
solid; yield 94%; Rf¼0.7 (20% EtOAc/hexanes); mp 102e103 ꢀC; 1H
1H), 2.43 (d, J¼0.9 Hz, 3H); 13C NMR (CDCl3, 75 MHz)
d
163.1 (d,
NMR (CDCl3, 300 MHz)
d
8.58 (d, J¼9.0 Hz, 2H), 8.03 (td, J¼8.4,
1JCeF¼246.8 Hz),140.2,138.7, 133.4 (d, 4JCeF¼2.9 Hz),130.2,128.7 (d,
0.6 Hz, 2H), 7.82 (ddd, J¼8.4, 6.9, 1.5 Hz, 1H), 7.53 (ddd, J¼8.4, 6.9,
1.5 Hz, 1H), 7.03 (d, J¼9.0 Hz, 2H), 3.89 (s, 3H), 2.98 (s, 3H).
3JCeF¼8.4 Hz), 124.7, 120.5, 117.9, 115.6, 115.3 (d, JCeF¼10.7 Hz),
2
78.8, 12.4; IR
n
(KBr) 3284, 1602, 1505, 1203, 752 cmꢂ1; HRMS (EI)
m/z calcd for C15H13FN2O [Mþ] 256.1012, found 256.1015.
4.4.4. 4-Methyl-2-(4-bromophenyl)quinazoline (4d). White solid;
yield 76%; Rf¼0.6 (20% EtOAc/hexanes); mp 207e208 ꢀC; 1H NMR
4.3.9. 2-(4-Cyanophenyl)-4-methyl-1,2-dihydroquinazoline 3-oxide
(CDCl3, 300 MHz)
d
8.50 (d, J¼8.4 Hz, 2H), 8.07 (d, J¼8.1 Hz, 1H),
(1i). Yellow solid; yield 87%; Rf¼0.2 (70% EtOAc/hexanes); mp
8.04 (d, J¼8.4 Hz, 1H), 7.85 (ddd, J¼8.4, 6.9, 1.5 Hz, 1H), 7.63 (d,
174e175 ꢀC; 1H NMR (CDCl3, 300 MHz)
d
7.67 (d, J¼8.4 Hz, 2H), 7.60
J¼8.4 Hz, 2H), 7.53 (ddd, J¼8.4, 6.9,1.5 Hz,1H), 2.99 (s, 3H); 13C NMR
(d, J¼8.4 Hz, 2H), 7.25e7.20 (m, 2H), 6.96 (td, J¼8.1, 1.2 Hz, 1H), 6.88
(dd, J¼8.1, 1.2 Hz, 1H), 6.20 (d, J¼3.9 Hz, 1H), 4.92 (br s, 1H), 2.45 (s,
(CDCl3, 75 MHz) d 168.3, 159.1, 150.2, 137.1, 133.6, 131.6, 130.1, 129.1,
127.0, 125.1, 124.9, 122.9, 21.9; IR
n (KBr) 1572, 1547, 1341, 1005,
3H); 13C NMR (CDCl3, 75 MHz)
d
142.5, 141.0, 138.2, 132.2, 130.6,
762 cmꢂ1; HRMS (EI) m/z calcd for C15H11BrN2 [Mþ] 298.0106,
127.4, 124.8, 120.9, 118.2, 117.9, 115.8, 112.6, 78.6, 12.4; IR
3260, 2233, 1609, 1479, 747 cmꢂ1; HRMS (EI) m/z calcd for
16H13N3O [Mþ] 263.1059, found 263.1052.
n
(KBr)
found 298.0109.
C
4.4.5. 4-Methyl-2-(2-bromophenyl)quinazoline (4e). Yellow solid;
yield 83%; Rf¼0.8 (20% EtOAc/hexanes); mp 103e104 ꢀC; 1H NMR
4 . 3 .10 . 4 - M e t h yl - 2 - ( 4 - ( t r i fl u o ro m e t hyl ) p h e nyl ) - 1, 2 -
dihydroquinazoline 3-oxide (1j). Yellow solid; yield 89%; Rf¼0.2
(70% EtOAc/hexanes); mp 212e213 ꢀC; 1H NMR (CD3OD, 300 MHz)
(CDCl3, 300 MHz)
d
8.16 (ddd, J¼8.4, 1.2, 0.6 Hz, 1H), 8.12 (ddd,
J¼8.4, 1.2, 0.6 Hz, 1H), 7.92 (ddd, J¼8.4, 6.9, 1.5 Hz, 1H), 7.76 (dd,
J¼7.8, 1.8 Hz, 1H), 7.72 (dd, J¼7.8, 1.2 Hz, 1H), 7.68 (ddd, J¼8.1, 6.9,
1.2 Hz, 1H), 7.45 (td, J¼7.5, 1.5 Hz, 1H), 7.30 (td, J¼7.5, 1.5 Hz, 1H),
d
7.65e7.59 (m, 4H), 7.36 (dd, J¼8.1, 1.2 Hz, 1H), 7.23 (td, J¼7.5,
1.2 Hz, 1H), 6.87e6.82 (m, 2H), 6.22 (s, 1H), 2.46 (s, 3H); 13C NMR
3.04 (s, 3H); 13C NMR (CDCl3, 75 MHz)
d 168.2, 161.9, 149.7, 140.3,
(CD3OD, 75 MHz)
d
146.0, 143.4, 141.6, 133.0, 132.1 (q,
133.7, 133.5, 131.3, 130.1, 129.0, 127.6, 127.3, 124.9, 122.6, 121.8, 21.7;
IR
(KBr) 1548, 1434, 1342, 1022, 759 cmꢂ1; HRMS (EI) m/z calcd for
15H11BrN2 [Mþ] 298.0106, found 298.0109.
3
2JCeF¼32.5 Hz), 128.3, 126.7, 126.5 (q, JCeF¼3.9 Hz), 125.4 (q,
n
1JCeF¼269.7 Hz), 120.9, 117.6, 116.0, 79.6, 12.7; IR
n
(KBr) 3273, 2425,
C
1329, 1122, 750 cmꢂ1; HRMS (EI) m/z calcd for C16H13F3N2O [Mþ]
306.0980, found 306.0985.
4.4.6. 4-Methyl-2-(2-chlorophenyl)quinazoline (4f). Yellow solid;
yield 89%; Rf¼0.8 (20% EtOAc/hexanes); mp 111e112 ꢀC (lit.5i
4.3.11. 4-Methyl-2-(4-nitrophenyl)-1,2-dihydroquinazoline 3-oxide
110.3e111.6 ꢀC); 1H NMR (CDCl3, 300 MHz)
d
7.78 (ddd, J¼8.4, 1.5,
(1k). Yellow solid; yield 77%; Rf¼0.2 (70% EtOAc/hexanes); mp
0.6 Hz, 1H), 8.11 (ddd, J¼8.4, 1.5, 0.6 Hz, 1H), 7.92 (ddd, J¼8.4, 6.9,
1.2 Hz, 1H), 7.80e7.77 (m, 1H), 7.68 (ddd, J¼8.4, 6.9, 1.2 Hz, 1H),
7.54e7.51 (m, 1H), 7.43e7.36 (m, 2H), 3.04 (s, 3H).
166e167 ꢀC; 1H NMR (CDCl3, 300 MHz)
d
8.16 (d, J¼9.0 Hz, 2H), 7.75
(dd, J¼9.0 Hz, 2H), 7.25e7.21 (m, 2H), 6.97 (td, J¼8.1, 1.2 Hz, 1H),
6.91 (dd, J¼8.1, 1.2 Hz, 1H), 6.25 (d, J¼4.5 Hz, 1H), 4.90 (d, J¼4.5 Hz,
1H), 2.46 (d, J¼0.6 Hz, 3H); 13C NMR (CDCl3, 75 MHz)
d
148.1, 144.3,
4.4.7. 4-Methyl-2-(2,4-dichlorophenyl)quinazoline
(4g). Yellow
141.1, 138.0, 130.7, 127.8, 124.9, 123.6,121.2, 118.2,116.1, 78.5, 12.4; IR
solid; yield 85%; Rf¼0.8 (20% EtOAc/hexanes); mp 106e107 ꢀC; 1H